textproduct: Rapid City

KEY MESSAGES

- Unseasonably warm temperatures through Friday (10-20F above average).

- Critical fire wx expected over portions of northeastern WY Friday afternoon and evening

- Gusty northwest winds (gusts of up to 55 mph over the western SD plains) expected late Friday into early Saturday morning

- Much cooler this weekend with chances for light rain and possibly some snow Sunday.

DISCUSSION

(This Evening Through Thursday) Issued at 1223 PM MDT Thu Oct 22 2026

Current upper air analysis depicts upper ridge axis over the Central and Northern Plains. Skies over the CWA are mostly clear save for a few upper level clouds. Sfc stations are reporting southerly winds with temperatures in the upper 60s to upper 70s across much of the western SD plains. Slightly cooler temps (mid 60s) are present over northeastern WY and the Black Hills. Way off to our west, deepening upper trof/closed low has pushed on shore over CA. Temperatures will continue to climb this afternoon with many areas on the western SD plains hitting the 80 degree mark.

Much warmer temperatures expected Friday as WAA ramps up ahead of approaching upper trof and attendant cold front. Some spots on the western SD plains could approach 90. Downtown Rapid City and the airport will reach into the low to mid 80s, potentially breaking their daily record highs (the daily record high for downtown Rapid City for 10/23 was 82 set in 1952 and the record at the airport was 80 set in 1963). In addition to the above average temperatures, a tightening sfc pressure gradient courtesy of a developing low will support gusty southwest winds over northeastern WY. Winds over northeastern WY will begin to ramp up by mid-morning with sustained winds of 25 to 35 mph and gusts up to 50 mph. HDWI values are above the 95th percentile for Campbell into Weston and Crook Counties. All this in mind, we are expecting widespread critical fire wx conditions to develop by Friday afternoon. More details in our Fire Wx Discussion.

Strong cold front pushes through the forecast area late Friday evening into early Saturday morning. Strong 3-hr pressure rises of 4- 7 mb behind the front will support a brief period of strong northwesterly winds late Friday night/early Saturday morning as the front pushes through. These pressure rises combined with strong CAA and 850-700 mb winds of 30-50KT will support gusts of 45 to 55 mph across much of the western SD plains. Will continue to monitor for potential wind headlines overnight Friday into early Saturday. While some showers may accompany the front as it comes through, not expecting any significant precip overnight Friday into Saturday.

Saturday will be significantly and noticeably cooler with highs in the mid 40s to mid 50s. Winds will remain quite breezy over western SD through Saturday morning and early afternoon as the front exits the region. Upper level low over the desert SW will eject over the Central Plains by Sunday. Model guidance has continued to be in fairly good consensus of a band of light precip (rain and some snow) moving through the CWA Sunday afternoon into Sunday evening. Deterministic guidance is hinting at the potential for some light accumulations (perhaps an inch or two), especially over the higher elevations of the Black Hills and portions of northeastern WY. Though with warm ground temps and the timing of the precip (looking like the bulk of the precip will push through in the afternoon hours), have low confidence in any appreciable snow accumulation except for maybe in the highest elevations of the Black Hills.

Seasonable temps will continue through early next week as upper trof moves through the plains with quasi-zonal flow developing by the midweek. Next shot for precip looks to be in the Wed/Thu timeframe.

AVIATION

(For the 18Z TAFS Through 18Z Friday) Issued At 1103 AM MDT Thu Oct 22 2026

VFR conditions are forecast to continue through the TAF period.

Winds will be gusty at times out of the south to southeast. Much stronger southwest winds are forecast for NE WY for Friday beginning late in the TAF period and lasting well into the next TAF period. A strong cold front will push through the area Friday night, shifting strong winds from southwest to northwest.

FIRE WEATHER

Issued At 1223 PM MDT Thu Oct 22 2026

Widespread critical fire weather conditions expected over northeastern WY Friday afternoon and Friday evening. Southwest winds will pick up through Friday morning ahead of an approaching cold front. Sustained winds of 25 to 35 mph with gusts of up to 50 mph expected over northeastern WY by early Friday afternoon with these strong winds persisting through Friday evening. In addition to the winds, temperatures will climb in the upper 60s to 70s and humidities will drop to 13 to 20% by Friday afternoon. Taking into consideration the combination of dry fuels and very warm, dry, and windy conditions, have opted to upgrade the Fire Wx Watch to a Red Flag Warning.

Cold front will push through the region late Friday night with winds shifting to the northwest behind the front. Winds will remain quite gusty behind the front with gusts of 45 to 55 mph expected over the western SD plains. Winds will diminish through Saturday morning as the front moves out of the area. Not expecting any wetting precip with this front. Much cooler temperatures expected over the weekend with a chance for rain and snow Sunday.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...Red Flag Warning from 11 AM to 11 PM MDT Friday for WYZ314>317.